I only took the technical phone interview and received a rejection letter two days later. Therefore, I will focus on describing the phone interview.

I had a referral from a friend for a position at Twitch. Their recruiter initially contacted me for some cultural fit or behavioral questions. Following that, I was scheduled for a technical phone screen interview a few days later.

The nature of the questions asked during the phone interview was quite easy, but I became confused by the interviewer's phrasing. The problem involved finding a string within a tree, and the interviewer specified that the tree was unbalanced. I understood an unbalanced tree to mean a node might be missing a child node, except for leaf nodes.

I proceeded to use a Breadth-First Search (BFS) algorithm to write the code. After I finished coding, the interviewer emphasized again that it was an unbalanced tree and advised against using conditions for determining whether to go left or right from a node. This threw me off considerably, as I had assumed the tree was a binary search tree or at least sorted. I asked for further clarification, and the interviewer stated that the tree was not sorted. At this point, I realized the interviewer might have confused unsorted with unbalanced, as these are two entirely different concepts. I then modified my code.

The interviewer was still not satisfied and further stated that the tree could have a cycle. I thought to myself, "A tree with a cycle? I've never heard of such a thing." Perhaps they intended to use a tree to represent a graph.

Again, I further changed my code to handle the problem of a "cycle in the tree." The entire process took about 40 minutes before the question became completely clear. The tree the interviewer envisioned:

• Unbalanced tree meant an unsorted tree.
• The tree could have a cycle.

I believe these misunderstandings stem from the interviewer's interpretation of the tree data structure, or at least these concepts were new to me before this interview. For obvious reasons, I am glad I did not proceed further in the interview process.

Using BFS to search a string in an "unbalanced tree"